I just deployed a fix to the server signing implementation, so the sample client
needs to be fixed as well.
Test Plan:
Log in with the test client.
Run this request:
/api/v1/user/exercises?username=alangpierce&exercises=addition_1&exercises=multiplication_1&format=pretty
The request succeeds, and the response contains two elements.
Auditors: benkomalo

Enter the Khan Academy url you want to test against (unless you're running a local version, this'll be http://www.khanacademy.org)

A browser will pop up for you to walk through the authentication flow. When done, it will redirect you to a page that says "Ok" and in the URL there will be two parameter values you need: oauth_token and oauth_token_secret.

Go back to the test.py command line and enter your new token and secret.

You'll now have a loop that lets you run Khan Academy API queries, authenticated as the user you logged in as.